heater core flush

I tried flushing my heater core today by taking off the 2 hoses from the waterpump. It would flush one way pretty well, but not the other way. I'm asuming theres some sort of 1 way valve in there somewhere? Damn, I still have no heat. At least I did the TB bypass.
Are there any write ups online for doing the heater core flush?

Thanks

how did you flush the core? i hooked up a garden hose to the heater inlet hose and a bunch of black gunk came out the outlet hose, after running it for 5 minutes i put coolant back in and had red hot heat.

i just got done like 10 mins ago. i put the garden hose to outlet hose (the one of top of the waterpump) and water came out of inlet hose pretty well and clear. I put them back and added some coolant to radiator and heat started to work but still not HOT HOT yet but it flows warm now. Howveer i didnt try to put the hose in inlet and try to fflush away from outlet. Maybe i should try that.

how did you flush the core? i hooked up a garden hose to the heater inlet hose and a bunch of black gunk came out the outlet hose, after running it for 5 minutes i put coolant back in and had red hot heat.

I tried doing it both ways. On the inlet and the outlet. The inlet was the one that would actually flow though. The outlet hose would just build up pressure and nothing would come out the other end, so that's why I figured it had a one way valve. I probably just didn't leave it going through long enough. It started to get dark and I had to get it back together.

The is no check vale, you have a blockage in there somewhere.

Re'

The is no check vale, you have a blockage in there somewhere.

Re'

thanks! Looks like I will have to try it again sometime.